The present invention relates to a hitch and trailer apparatus and, in particular, to a hitch and trailer apparatus adapted to be pulled by a bicycle.
A number of trailer and hitch apparatus for use in conjunction with bicycles have been devised. One goal of such apparatus has been that back and forth or up and down motion of the bicycle be isolated from similar motion of the trailer so that complete and full control over the operation of the bicycle will not be impeded by the trailer.
Various universal joint mechanisms have been devised which attempt to achieve this goal. For example, in U.S. Pat. Nos. 624,678, issued May 9, 1889, to J. Planes; 3,567,249, issued Mar. 2, 1971, to R. S. Robinson and 3,877,723, issued Apr. 15, 1975, to Fahey, et al, various universal-type joint mechanisms are disclosed. However, each of these universal joints provide two or more orthogonal fixed axes about which rotation is permitted. Such an arrangement has been found to cause throbbing, that is, relative forward or backward motion between the bicycle and the trailer. Such throbbing motion significantly effects the ability of an operator to control the bicycle and, under certain circumstances, could cause the trailer to jack-knife or otherwise tend to tip over. By contrast, the present invention provides a fixed ball and socket arrangement which does not have any fixed axes of rotation but rather allows smooth and continuous rotation about substantially the entire ball. The ball and socket joint of the present invention substantially eliminates all throbbing and thus permits the bicycle operator to maintain control over the bicycle while towing the trailer.
Various ball and socket type joints have been utilized in trailer and hitch assemblies. For example, in U.S. Pat. No. Reissue 26,806, issued Mar. 30, 1970, to R. S. Robinson, a ball and socket arrangement is disclosed whereby the ball is attached to the axle of a bicycle wheel. By contrast, the present invention provides a ball attached to the frame above the wheel thus allowing substantially more freedom of movement of the bicycle in turning situations.
In U.S. Pat. No. 4,077,645, issued Mar. 7, 1978, to Dortch, et al, a ball and socket type interconnecting hitch is disclosed. However, in that arrangement, the interconnecting member has a hook-like neck so that the interconnection to the ball is made vertically from a top of the ball. Such a neck protrusion could cause injury to an operator in case of an accident.
In U.S. Pat. No. 4,077,646, issued Mar. 7, 1978, to Watkins, another ball and socket type hitch arrangement is shown. However, reference to FIG. 5 shows that in order to provide maximum side-to-side motion of the bicycle, the ball must be rotated so that the connecting stem is substantially in a horizontal orientation rather than a vertical orientation. Thus, the ball and socket apparatus disclosed is substantially limited in its freedom of movement. In addition, a substantial problem of keeping the socket on the ball would arise utilizing the arrangement shown in FIG. 5.
Finally, in U.S. Pat. No. 3,492,024, issued Jan. 27, 1970, to J. H. Cooper, a trailer hitch for motorcycles is shown incorporating a ball and socket type arrangement. However, the arrangement illustrated does not provide for any substantially side-to-side motion. Indeed, in each of the above-identified ball and socket type interconnecting apparatus, a primary purpose of the apparatus is to provide a means for coupling and decoupling the trailer from the bicycle. Thus, each apparatus incorporates an attachment mechanism in the bolt and socket joint which inhibits free motion of the socket about the ball. By contrast, in the present invention, the socket is permanently attached to the ball. Disconnection of the trailer from the bicycle occurs by providing a hitch portion to the swivel or socket member. The hitch portion has a first passageway into which a rigid attachment portion fixed to the trailer may be inserted. A transverse hole or passageway intersects the first passageway. The orifice in the end of the rigid swivel attachment end is aligned with the second passageway and thereafter held in place by a spring loaded release pin.
The trailer may be released from the bicycle by simply removing the release pin and extracating the rigid attachment end from the first passageway in the swivel member. Because the connection and disconnection is not made by removing the ball from the socket, a retention plate member may be utilized to allow far greater freedom of movement of the ball within the socket and thus more completely isolates movement of the bicycle from the trailer and vice versa. Because of the greater freedom in motion, utilizing the present invention, the bicycle may be laid down on the ground without causing the trailer to tip or otherwise be upset.
Thus, the present invention provides a novel means by which only the bicycle's forward motion is imparted to the trailer and all other relative motion between the trailer and the bicycle is isolated so that motion of the bicycle does not affect the trailer and motion of the trailer does not affect the bicycle. In addition, the present invention provides a means by which the trailer may be quickly and easily disconnected from the bicycle and hand pulled.
A permanent ball and socket type interconnection is shown in U.S. Pat. No. 4,037,853, issued July 26, 1977, to Sparks, and in U.S. Pat. No. 2,370,988, issued Mar. 6, 1945, to Neal. However, in these patents the ball and socket type interconnecting is such that motion between the trailer and bicycle is substantially coupled or otherwise limited. In addition, neither of these two patents provide for any quick disconnection mechanism. For example, in Sparks, the disconnection must be made by unscrewing a bolt by which the ball member is attached to the bicycle. By contrast, the present invention is a very simple mechanism which substantially isolates motion between the trailer and bicycle, except in the forward or pulling direction. Because of the simplicity of the present invention, it is substantially less expensive and easier to build than prior devices.